New Technology Uses Dredged Material for Restoration, Cement

Sediments dredged from the bottoms of lakes can be difficult to dispose of, but two new studies have found uses for the material.

At a recent study site at the Bark Camp Demonstration Project in Clearfield County, PA, almost 500,000 cubic yards of dredged materials was mixed with coal ash that hardened to form an engineered fill with structural integrity, very low permeability and resistance to acid attack. This allows rainwater to run off the site instead of mixing with pyritic materials that otherwise would turn the water into polluted acid mine drainage, a leading cause of water pollution in Pennsylvania. The Bark Camp project successfully brought the area back to grade and thereby removed physical hazards, returned surface waters to their watersheds, restored natural vegetation, and restored habitat and characteristics to a previously scarred strip of mine land about 1.5-miles long. To see more about this project, visit http://www.nynjcoast.org/AMR/barkcampreport.html.

Another study performed by the EPA and other partners in New Jersey has shown promise for turning dredged material into a substance that can be used to make construction-grade cement. The Cement Lock technology was designed to destroy certain contaminants in dredged material, "lock up" or immobilize metals and ultimately produce a product similar to portland cement. EPA expects Cement-Lock to be used to treat dredged sediments from a variety of sites in the New York/New Jersey harbor, with an ultimate goal of creating a self-sustaining industry that uses treated dredged sediments as building material. For more information about this technology, visit http://www.epa.gov/region02/news/2003/03138.htm.

In a related story, PA State Representative David Argall has recently proposed a bill to allow Pennsylvania municipalities the authority over the PA DEP to regulate or prohibit dredged material disposal in their communities. To view the proposed bill, visit http://www.daveargall.com/uploads/riverdredgebill.pdf.